Re: [PATCH RFC] iio: pressure: zpa2326: report interrupted case as failure

[Jonathan Cameron]

On 14/05/17 10:46, Peter Meerwald-Stadler wrote:
> > If the timeout-case prints a warning message then probably the interrupted
> > case should also. Further, wait_for_completion_interruptible_timeout()
> > returns long not int.
> >
> > Fixes: commit 03b262f2bbf4 ("iio:pressure: initial zpa2326 barometer support")
> > Signed-off-by: Nicholas Mc Guire <der.herr@xxxxxxx>
>
> this is actually a v2, looks good to me
A formal ack would be good!  Anyhow, I'll take that as an informal one.

A typo in the error message that I've fixed.

Applied to the togreg branch of iio.git.  Will be pushed out as testing
for the autobuilders to play with it.

BTW I don't think this one really should have been an RFC. It's a clear
tidy up to some confusing code being proposed for inclusion rather than
to start a discussion!

Jonathan
> > ---
> >
> > The original control-flow was technically not wrong just confusing and a bit
> > complicated. Not clear if reporting the interrupted case actually is useful,
> > but given that the timeout is relatively long (200ms) it is not that unlikely
> > so differentiating the cases seems helpful.
> >
> > Patch was compile-tested with: x86_64_defconfig + CONFIG_IIO=m, CONFIG_ZPA2326=m
> >
> > Patch is against v4.11 (localversion-next is next-20170512)
> >
> >   drivers/iio/pressure/zpa2326.c | 17 ++++++++++-------
> >   1 file changed, 10 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/iio/pressure/zpa2326.c b/drivers/iio/pressure/zpa2326.c
> > index e58a0ad..617926f 100644
> > --- a/drivers/iio/pressure/zpa2326.c
> > +++ b/drivers/iio/pressure/zpa2326.c
> > @@ -867,12 +867,13 @@ static int zpa2326_wait_oneshot_completion(const struct iio_dev   *indio_dev,
> >   {
> >   	int          ret;
> >   	unsigned int val;
> > +	long     timeout;
> >   
> >   	zpa2326_dbg(indio_dev, "waiting for one shot completion interrupt");
> >   
> > -	ret = wait_for_completion_interruptible_timeout(
> > +	timeout = wait_for_completion_interruptible_timeout(
> >   		&private->data_ready, ZPA2326_CONVERSION_JIFFIES);
> > -	if (ret > 0)
> > +	if (timeout > 0)
> >   		/*
> >   		 * Interrupt handler completed before timeout: return operation
> >   		 * status.
> > @@ -882,13 +883,15 @@ static int zpa2326_wait_oneshot_completion(const struct iio_dev   *indio_dev,
> >   	/* Clear all interrupts just to be sure. */
> >   	regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val);
> >   
> > -	if (!ret)
> > +	if (!timeout) {
> >   		/* Timed out. */
> > +		zpa2326_warn(indio_dev, "no one shot interrupt occurred (%ld)",
> > +			     timeout);
> >   		ret = -ETIME;
> > -
> > -	if (ret != -ERESTARTSYS)
> > -		zpa2326_warn(indio_dev, "no one shot interrupt occurred (%d)",
> > -			     ret);
> > +	} else if (timeout < 0) {
> > +		zpa2326_warn(indio_dev, "wait for one shot interrupt canceled");
cancelled. I'll fix that.
> > +		ret = -ERESTARTSYS;
> > +	}
> >   
> >   	return ret;
> >   }